Plants herbaceous rosettes, erect self-supporting tree-like, or pendulous, or scrambling, or curtain-forming; rhizomes usually pachymorph, or leptomorph, or both. Culms absent or to 18m tall, caespitose, diffuse or pluricespitose; internodes usually solid, often hollow, terete or shallowly grooved above branches; nodes level or more or less swollen, the supranodal ridge obscure or well-developed, nodal line horizontal or diving well below branches. Branches completely absent, or initially 3, or up to several hundred, central and laterals equal, subequal, dimorphic or trimorphic, fully sheathed or with several to most sheaths much reduced, intravaginal, extravaginal, or infravaginal; buds absent, few or multitudinous, at mid-culm often very open at front, prophylls usually absent, few to many subsidiary axes exposed, or higher orders of branching apparently from separate buds, or actually from many buds on opposite sides or all around the culm. Culm sheaths absent, or delicate and deciduous, or tough and persistent; blades deciduous and articulating to scarcely defined, erect or reflexed. Leaf sheaths generally persistent, or deciduous, delicate to greatly thickened; blades very broad to needle-like, with or without prominently tessellate venation, erect or deflexed. Synflorescence semelauctant, ebracteate, open and paniculate, or dense and capitate. Spikelets with single florets; glumes (2)-4; lemmas mucronate; paleas unkeeled to 2-keeled; rhachilla extension absent; stamens 3; style with 2 plumose stigmas. Name from Chusque, the local name for species including the type species Chusquea scandens, in Colombia and Ecuador.
Chusquea is a New World tropical to temperate genus, currently interpreted very broadly indeed on the basis of the criterion of molecular monophyly and including up to 200 species, found from NW Mexico across to E Brazil, the West Indies, and down to S Chile. Included within it are 3 subgenera and 3 sections that would be considered distinct genera if found in Asia, as well as 26 peculiar species that cannot currently be placed in any subgenus or section.
While some species are clearly bamboos, several species do not really look like bamboos at all, and from a distance could easily be mistaken as, for example, a reed, a dwarf conifer, a Sisyrinchium, a Phormium, while in several species the whorls of short branches with narrow leaves right around the culm nodes can give the appearance of a giant horsetail.
There is so much morphological diversity within Chusquea, as currently recognised in this very broad sense, that it is impossible to generalise most morphological characters at all, except for its spikelets, which are more consistent and have only one floret. Thus the genus has very limited value for field identification, and 2 infrageneric ranks of different subgenera and sections need to be used. There would appear to be something of a mismatch between generic concepts applied to bamboos in Asia, where a binomial system of genus and species is sufficient for identification, and the Americas, where a 3-4 ranked system is required.
Fortunately from the point of view of identification of cultivated plants, only a small number of species have made it into horticulture. This is partly because the number of truly hardy species of Chusquea is very small, and most of the tender species are quite demanding in their requirements. Many species are not well suited to cultivation simply because they are scramblers and not self-supporting. Others just don’t even look remotely like a traditional bamboo in the first place, so they have not been collected for cultivation as bamboos.